1. Field of the Invention
The present invention relates generally to storage of hazardous materials. More specifically, the present invention relates to the storage of liquid hazardous material in double containment devices.
2. Description of the Prior Art
Liquid hazardous materials have become commonplace in our society. They can be seen as pesticides in our hardware stores, used motor oil in our garages and in various forms in our manufacturing and research facilities. Seepage from these and other sources pose a significant health risk. Local and national agencies have begun regulating these materials as a result. This regulation will continually be expanded and increased
Currently, in a significant number of jurisdictions, the law regarding regulation of these materials calls for storage in a double containment device. The current practice is to store these materials in a simple tray having sides. The trays are placed on shelves where they can be readily accessed by the researcher in the laboratory or the customer in the hardware store, etc. The bottle in which the substance is stored is the first container, the tray is the second container, thus fulfilling a double container storage requirement.
Recent changes in codes and regulations provide that any container that holds liquid hazardous material (CLHM) is now required to be stored in a secondary container that will hold 150% of the volume of the hazardous material. These new codes allow storage of more than one container of hazardous material in one secondary container, as long as the secondary container can hold (1) 150% of the largest CLHM volume or (2) 10% of the aggregate volume being stored.
In the first case, a large container can be placed in a tray (which is 150% of the container's volume) and any portion of the tray left available may be filled with as many smaller containers as will fit. In the second case, if 10 one pint bottles are to be stored in a tray, the tray which is the second container must have a volume of at least 1 pint.
The method now used for storing chemicals precludes the use of one double containment devise per CLHM, due to the loss of storage space. Storing more than one CLHM per tray, however, results in another problem: the reduction in the volume of the secondary containment device (the tray) by the displacement volume of each bottle added, i.e , only the spaces between the CLHMs could contain the spills.
Thus, the greater the number of bottles stored in a tray (the greater the efficiency), the less volume that can be stored because of the reduction in second container volume. Also, this flux of second container volume makes it difficult to readily ascertain or calculate the volume of the second container.
There are additional shortcomings to the present system of storage. One is that of "floaters," a half full bottle of chemical placed in the tray which floats during a spill. For example, when there is a spill from another bottle in the same tray the half full bottle may float up and possibly fall over the side. Its impact with the floor could cause a hazardous spill. Another shortcoming is the inefficient use of storage space. Particularly, the volume of the shelf itself could more efficiently be used for liquid hazardous material storage. Furthermore, the high walled trays obscure the view of a bottle's contents label making it difficult and time consuming to locate a particular bottle.
Additional shortcomings of prior art methods now prevalently in use include poor earthquake survival potential, difficult accessibility for clean-up, and difficult regulation enforcement due to inconsistent and often overused storage methods.